The crown-of-thorns starfish (Acanthaster planci) is a venomous starfish. In this study, the extraction of A. planci spine
venom (ASV) was performed by
phosphate saline
buffer, followed by assaying the cytotoxicity on human normal and
tumor cells. It was found that human
melanoma cells (A375.S2) were the most sensitive to the ASV
solution. The cells, after incubation with ASV, significantly appeared to decrease cell viability and increase
lactate dehydrogenase (LDH) release with a dose-dependent relationship. The extract of spine promoted loss of mitochondrial membrane potential (ΔΨm) and induced inter-nucleosomal DNA fragmentation in human
melanoma cells. The cells exhibited apoptosis by using
propidium iodide (PI) staining of DNA fragmentation; it was then determined by flow cytometry (sub-G1 peak). The molecular cytotoxicity of ASV was tested through evaluation of the apoptosis/
necrosis ratio by double staining with
annexin V and PI assay. The A. planci spine
venom showed significant antiproliferation. The human
melanoma cells revealed apoptosis at low dose (1.25 μg/ml), and
necrosis occurred at high dose (5 μg/ml).